Displaying publications 41 - 60 of 89 in total

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  1. Rahman LF, Marufuzzaman M, Alam L, Sidek LM, Reaz MBI
    PLoS One, 2020;15(2):e0225408.
    PMID: 32023244 DOI: 10.1371/journal.pone.0225408
    A high-voltage generator (HVG) is an essential part of a radio frequency identification electrically erasable programmable read-only memory (RFID-EEPROM). An HVG circuit is used to generate a regulated output voltage that is higher than the power supply voltage. However, the performance of the HVG is affected owing to the high-power dissipation, high-ripple voltage and low-pumping efficiency. Therefore, a regulator circuit consists of a voltage divider, comparator and a voltage reference, which are respectively required to reduce the ripple voltage, increase pumping efficiency and decrease the power dissipation of the HVG. Conversely, a clock driving circuit consists of the current-starved ring oscillator (CSRO), and the non- overlapping clock generator is required to drive the clock signals of the HVG circuit. In this study, the Mentor Graphics EldoSpice software package is used to design and simulate the HVG circuitry. The results showed that the designed CSRO dissipated only 4.9 μW at 10.2 MHz and that the phase noise was only -119.38 dBc/Hz at 1 MHz. Moreover, the proposed charge pump circuit was able to generate a maximum VPP of 13.53 V and it dissipated a power of only 31.01 μW for an input voltage VDD of 1.8 V. After integrating all the HVG modules, the results showed that the regulated HVG circuit was also able to generate a higher VPP of 14.59 V, while the total power dissipated was only 0.12 mW with a chip area of 0.044 mm2. Moreover, the HVG circuit produced a pumping efficiency of 90% and reduced the ripple voltage to <4 mV. Therefore, the integration of all the proposed modules in HVG ensured low-ripple programming voltages, higher pumping efficiency, and EEPROMs with lower power dissipation, and can be extensively used in low-power applications, such as in non-volatile memory, radiofrequency identification transponders, on-chip direct current DC-DC converters.
  2. Ismail NH, Ibrahim SF, Mokhtar MH, Yahaya A, Zulkefli AF, Ankasha SJ, et al.
    Front Endocrinol (Lausanne), 2023;14:1031066.
    PMID: 36923220 DOI: 10.3389/fendo.2023.1031066
    INTRODUCTION: Vulvovaginal atrophy (VVA) is a common condition in post-menopausal women. Symptoms of VVA include dyspareunia, vaginal dryness, vaginal and/or vulvar itching, burning and soreness, dysuria and vaginal bleeding accompanying sexual activity. These symptoms are physiological responses to hypoestrogenicity, inducing atrophy of the vagina epithelia and sudden reduction in mucous production. Prevailing therapy for VVA is hormone replacement therapy (HRT), notably estrogen, progesterone or a combination of the two. However, using HRT is associated with an increased incidence of breast and endometrial cancer, venous thromboembolism in the lungs and legs, stroke and cardiovascular complications.

    METHODS: This study evaluated Malaysian Gelam honey as a nutraceutical alternative to estrogen HRT (ERT) in alleviating VVA. A total of 24 female 8-weekold Sprague Dawley rats underwent bilateral oophorectomy. A minimum of 14 days elapsed from the time of surgery and administration of the first dose of Gelam honey to allow the female hormones to subside to a stable baseline and complete recovery from surgery. Vaginal tissues were harvested following a 2-week administration of Gelam honey, the harvested vagina tissue underwent immunohistochemistry (IHC) analysis for protein localization and qPCR for mRNA expression analysis.

    RESULTS: Results indicated that Gelam honey administration had increased the localization of Aqp1, Aqp5, CFTR and Muc1 proteins in vaginal tissue compared to the menopause group. The effect of Gelam honey on the protein expressions is summarized as Aqp1>CFTR>Aqp5>Muc1.

    DISCUSSION: Gene expression analysis reveals Gelam honey had no effect on Aqp1 and CFTR genes. Gelam honey had up-regulated Aqp5 gene expression. However, its expression was lower than in the ERT+Ovx group. Additionally, Gelam honey up-regulated Muc1 in the vagina, with an expression level higher than those observed either in the ERT+Ovx or SC groups. Gelam honey exhibits a weak estrogenic effect on the genes and proteins responsible for regulating water in the vaginal tissue (Aqp1, Aqp5 and CFTR). In contrast, Gelam honey exhibits a strong estrogenic ability in influencing gene and protein expression for the sialic acid Muc1. Muc1 is associated with mucous production at the vaginal epithelial layer. In conclusion, the protein and gene expression changes in the vagina by Gelam honey had reduced the occurrence of vaginal atrophy in surgically-induced menopause models.

  3. Bhatti SM, Al Mamun A, Wu M, Naznen F, Kanwal S, Makhbul ZKM
    Environ Sci Pollut Res Int, 2023 Sep;30(44):99855-99874.
    PMID: 37615918 DOI: 10.1007/s11356-023-29353-4
    The current global trend in sustainable business practices is to optimize green innovation performance. To protect the environment and maintain their own survival, organizations must strengthen their green innovation capabilities. Drawing on the recourse-based view and ecology modernization theory (EMT), this study examines the direct effect of green strategic orientations, green entrepreneurial orientation, green market orientation, green innovation orientation, and green organizational culture on the firm's green innovation capability, as well as the mediating effect of green innovation capability on the relationship of these four factors and green innovation performance. Besides, this study also explored the moderating effects of green management system implementation and firm size on the association between green innovation capability and green innovation performance. To test the hypothesized model, a questionnaire survey was administered to gather responses from 293 medium-sized and large manufacturing firms operating in Pakistan. The partial least squares method was used for data analysis. The results revealed that green entrepreneurial orientation, green market orientation, green innovation orientation, and green organizational culture positively impacted green innovation capability, which subsequently positively influenced green innovation performance. Moreover, effective implementation of green management systems can bolster the effect of green innovation capability on green innovation performance, and the mediating effect of green innovation capability has also been confirmed. These indicated that the management of medium and large manufacturing firms operating in Pakistan should focus on encouraging green innovation and training employees regarding the latest eco-friendly technologies to attain performance and sustainable development goals. Policymakers should implement green business development programs and offer rewards or penalties for promoting compliance. The present study contributes greatly to the literature by applying EMT as an alternative to address the mediating role of green innovation capability and the moderating effect of green management system implementation in enhancing firms' green innovation performance.
  4. Rad SK, Arya A, Karimian H, Madhavan P, Rizwan F, Koshy S, et al.
    Drug Des Devel Ther, 2018;12:3999-4021.
    PMID: 30538427 DOI: 10.2147/DDDT.S173970
    The pathophysiological link between type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has been suggested in several reports. Few findings suggest that T2DM has strong link in the development process of AD, and the complete mechanism is yet to be revealed. Formation of amyloid plaques (APs) and neurofibrillary tangles (NFTs) are two central hallmarks in the AD. APs are the dense composites of β-amyloid protein (Aβ) which accumulates around the nerve cells. Moreover, NFTs are the twisted fibers containing hyperphosphorylated tau proteins present in certain residues of Aβ that build up inside the brain cells. Certain factors contribute to the aetiogenesis of AD by regulating insulin signaling pathway in the brain and accelerating the formation of neurotoxic Aβ and NFTs via various mechanisms, including GSK3β, JNK, CamKII, CDK5, CK1, MARK4, PLK2, Syk, DYRK1A, PPP, and P70S6K. Progression to AD could be influenced by insulin signaling pathway that is affected due to T2DM. Interestingly, NFTs and APs lead to the impairment of several crucial cascades, such as synaptogenesis, neurotrophy, and apoptosis, which are regulated by insulin, cholesterol, and glucose metabolism. The investigation of the molecular cascades through insulin functions in brain contributes to probe and perceive progressions of diabetes to AD. This review elaborates the molecular insights that would help to further understand the potential mechanisms linking T2DM and AD.
  5. Tan SC, Lim PY, Fang J, Mokhtar MFM, Hanif EAM, Jamal R
    Sci Rep, 2020 Feb 26;10(1):3508.
    PMID: 32103099 DOI: 10.1038/s41598-020-60442-3
    Numerous studies have investigated the association of MIR499A rs3746444 polymorphism with breast cancer susceptibility, but the results have been inconsistent. In this work, we performed a meta-analysis to obtain a more reliable estimate of the association between the polymorphism and susceptibility to breast cancer. A comprehensive literature search was conducted on PubMed, Scopus, Web of Science (WoS), China National Knowledge Infrastructure (CNKI), VIP and Wanfang databases up to January 2020. A total of 14 studies involving 6,797 cases and 8,534 controls were included for analysis under five genetic models: homozygous (GG vs. AA), heterozygous (AG vs. AA), dominant (AG + GG vs. AA), recessive (GG vs. AA + AG) and allele (G vs. A). A statistically significant association was observed between the polymorphism and an increased breast cancer susceptibility under all genetic models (homozygous, OR = 1.33, 95% CI = 1.03-1.71, P = 0.03; heterozygous, OR = 1.08, 95% CI = 1.00-1.16, P = 0.04; dominant, OR = 1.15, 95% CI = 1.02-1.30; P = 0.03; recessive, OR = 1.35, 95% CI = 1.06-1.72, P = 0.01; allele, OR = 1.12, 95% CI = 1.00-1.26, P = 0.04). Subgroup analysis based on ethnicity suggested that significant association was present only among Asians, but not Caucasians. In conclusion, MIR499A rs3746444 polymorphism was significantly associated with breast cancer susceptibility among Asians, suggesting its potential use as a genetic risk marker in this population.
  6. Al Mamun A, Naznen F, Yang Q, Ali MH, Hashim NMHN
    Heliyon, 2023 Jun;9(6):e16765.
    PMID: 37292299 DOI: 10.1016/j.heliyon.2023.e16765
    Due to the major shift in online purchasing during the COVID-19 lockdown, celebrity endorsement marketing has gained traction. Concurrently, COVID-19 has also transformed consumers' attitudes toward using eco-friendly products, such as green skincare products, to ensure a healthier lifestyle. This study developed a comprehensive framework based on the stimuli-organism-response theory and the parasocial interaction theory to empirically evaluate the impact of celebrities' credibility attributes and consumers' interests in celebrities on their attitudes towards advertisements for endorsed green skincare products, their intentions to make a purchase, and their willingness to pay a premium price for these products. 778 Malaysian consumers participated in the online survey, and their responses were analyzed using partial least squares structural equation modelling (PLS-SEM). The results showed the positive effects of credibility traits (trustworthiness - β = 0.100, p-value = 0.026; exquisite personality - β = 0.075, p-value = 0.028; dignified image - β = 0.152, p-value = 0.001; expertise - β = 0.221, p-value <0.001), and customer attention to celebrities (β = 0.184, p-value <0.001) on their attitudes toward endorsed advertisements. Likewise, credibility features (exquisite personality - β = 0.116, p-value = 0.002; dignified image - β = 0.112, p-value = 0.017; expertise - β = 0.207, p-value <0.001) and customers' companionship with celebrities (β = 0.142, p-value = 0.001) also have a significant positive impact on attitudes towards brands. Finally, consumers' purchasing intentions and willingness to pay premium prices for green skincare products were strongly influenced by their attitude toward advertising (β = 0.484, p-value <0.001) and brands (β = 0.326, p-value <0.001). Evidently, the findings of this study may help players in the cosmetics industry enhance their marketing and promotion tactics for eco-friendly beauty and personal care products.
  7. Neo EX, Hasikin K, Mokhtar MI, Lai KW, Azizan MM, Razak SA, et al.
    Front Public Health, 2022;10:851553.
    PMID: 35664109 DOI: 10.3389/fpubh.2022.851553
    Environmental issues such as environmental pollutions and climate change are the impacts of globalization and become debatable issues among academics and industry key players. One of the environmental issues which is air pollution has been catching attention among industrialists, researchers, and communities around the world. However, it has always neglected until the impacts on human health become worse, and at times, irreversible. Human exposure to air pollutant such as particulate matters, sulfur dioxide, ozone and carbon monoxide contributed to adverse health hazards which result in respiratory diseases, cardiorespiratory diseases, cancers, and worst, can lead to death. This has led to a spike increase of hospitalization and emergency department visits especially at areas with worse pollution cases that seriously impacting human life and health. To address this alarming issue, a predictive model of air pollution is crucial in assessing the impacts of health due to air pollution. It is also critical in predicting the air quality index when assessing the risk contributed by air pollutant exposure. Hence, this systemic review explores the existing studies on anticipating air quality impact to human health using the advancement of Artificial Intelligence (AI). From the extensive review, we highlighted research gaps in this field that are worth to inquire. Our study proposes to develop an AI-based integrated environmental and health impact assessment system using federated learning. This is specifically aims to identify the association of health impact and pollution based on socio-economic activities and predict the Air Quality Index (AQI) for impact assessment. The output of the system will be utilized for hospitals and healthcare services management and planning. The proposed solution is expected to accommodate the needs of the critical and prioritization of sensitive group of publics during pollution seasons. Our finding will bring positive impacts to the society in terms of improved healthcare services quality, environmental and health sustainability. The findings are beneficial to local authorities either in healthcare or environmental monitoring institutions especially in the developing countries.
  8. Al Mamun A, Naznen F, Yang M, Yang Q, Wu M, Masukujjaman M
    Sci Rep, 2023 Jul 11;13(1):11217.
    PMID: 37433838 DOI: 10.1038/s41598-023-38333-0
    This study aims to examine the mediating effect of the intention to use wearable payment devices (WPD) between perceived ease of use (PE), perceived usefulness (PU), social influence (SI), perceived trust (TR), and lifestyle compatibility (CM) on the adoption of WPD. Examination was made on the moderating effect of age and gender to improve the understanding of the adoption of WPD as a new payment system. Empirical data was collected through an online survey from 1094 respondents in Malaysia. Furthermore, this study employed dual-stage data analysis through partial least squares structural equation modelling (PLS-SEM) to test the causal and moderating effects, including artificial neural network (ANN) to examine the predictive power of the selected model. As a result, it was found that PE, PU, TR, and CM had a significant positive influence on the intention to use WPD. Furthermore, facilitating conditions and the intention to use WPD exhibited strong positive impacts on the adoption of WPD among Malaysian youth. The intention to use WPD positively and significantly mediated all predictors of adoption of WPD. Following that, ANN analysis confirmed high prediction accuracy of the data fitness. Overall, the findings for ANN highlighted the importance of PE, CM, and TR on the intention to adopt WPD and the impact of facilitating conditions on the adoption of WPD among Malaysian youth. Theoretically, the study extended UTAUT with two additional determinants (e.g., perceived trust and lifestyle compatibility), which were found to have significant influences on the intention to use WPD. The study results would be able to help payment service providers and the smart wearable device industry offer an innovative spectrum of products and present effective marketing tactics to encourage the prospective consumers of Wearable Payment Devices in Malaysia.
  9. Yang Q, Al Mamun A, Naznen F, Siyu L, Mohamed Makhbul ZK
    Heliyon, 2023 Jun;9(6):e17487.
    PMID: 37416654 DOI: 10.1016/j.heliyon.2023.e17487
    The present research aims to extend the value-belief-norm model by including health values, health consciousness, healthy eating beliefs, and trust in organic food as the impelling factors. This study empirically tested the holistic framework to understand the important factors in consumers' decision-making processes concerning organic food consumption. A web-based survey was performed to collect data from a convenience sample of 571 organic food consuming university students in China. The hypotheses were tested using partial least square structural equation modelling (PLS-SEM). Based on the findings, health values and health consciousness had substantial impacts on healthy eating beliefs, which in turn positively affected personal norms and awareness of consequences. Additionally, awareness of consequences and ascription of responsibility had major effects on personal norms. Likewise, personal norms and trust in organic food had a profound influence on the intention to consume organic foods, which in turn significantly induced actual consumption. The findings not only provide novel insights for researchers to understand the aspects of organic food consumption but present a guideline for marketers to develop appropriate marketing tactics to grow the organic food business. This study recommends that policymakers should focus on increasing the awareness and knowledge of organic food, encouraging organic food production, and prioritising campaigns showcasing the unique health benefits of organic food to stimulate increased consumption.
  10. Al Mamun A, Yang Q, Naznen F, Aziz NA, Masud MM
    Heliyon, 2023 Aug;9(8):e18998.
    PMID: 37609413 DOI: 10.1016/j.heliyon.2023.e18998
    As a safe alternative to hazardous agrochemicals, food waste compost could prevent human health hazards and environmental degradation. Food waste composting has not garnered much popularity among farmers given their sole dependence on synthetic fertilizers for high yields and commercial returns. Hence, this study aimed to identify the factors influencing farmers' adoption of food waste composting for regular use. Empirical data were collected from 399 farmers residing in different second-tier cities in China through face-to-face interviews using a structured questionnaire. The partial least squares-structural equation modelling was used to statistically examine the models and construct correlations. Based on the study outcomes, the perceived usefulness of food waste compost, awareness of the consequences, social influence, anticipated guilt, and attitude towards food waste composting substantially impacted food waste composting intention. Intriguingly, the perceived value of sustainability and ascription of responsibility did not have a significant impact on food waste composting intention, whereas food waste composting intention substantially influenced food waste composting behavior. The results of the multi-group analysis revealed differences in the relationship between awareness of consequences and food waste composting intention across genders and educational levels. This intriguing finding provides new avenues for future research and offers novel insights into the practical applications and promotion of food waste composting. These results will improve the relevant aspects among farmers for eco-friendly farming practices, innovate food waste management strategies, and mitigate environmental deterioration resulting from hazardous agrochemicals. This study expands the current body of literature by providing government regulators and other social enterprises with effective laws, policies, and strategy development guidelines for adopting natural composting on a large scale and enhancing the nutritional value of food to prevent unforeseen health risks caused by toxic chemicals.
  11. Neo EX, Hasikin K, Lai KW, Mokhtar MI, Azizan MM, Hizaddin HF, et al.
    PeerJ Comput Sci, 2023;9:e1306.
    PMID: 37346549 DOI: 10.7717/peerj-cs.1306
    BACKGROUND: The environment has been significantly impacted by rapid urbanization, leading to a need for changes in climate change and pollution indicators. The 4IR offers a potential solution to efficiently manage these impacts. Smart city ecosystems can provide well-designed, sustainable, and safe cities that enable holistic climate change and global warming solutions through various community-centred initiatives. These include smart planning techniques, smart environment monitoring, and smart governance. An air quality intelligence platform, which operates as a complete measurement site for monitoring and governing air quality, has shown promising results in providing actionable insights. This article aims to highlight the potential of machine learning models in predicting air quality, providing data-driven strategic and sustainable solutions for smart cities.

    METHODS: This study proposed an end-to-end air quality predictive model for smart city applications, utilizing four machine learning techniques and two deep learning techniques. These include Ada Boost, SVR, RF, KNN, MLP regressor and LSTM. The study was conducted in four different urban cities in Selangor, Malaysia, including Petaling Jaya, Banting, Klang, and Shah Alam. The model considered the air quality data of various pollution markers such as PM2.5, PM10, O3, and CO. Additionally, meteorological data including wind speed and wind direction were also considered, and their interactions with the pollutant markers were quantified. The study aimed to determine the correlation variance of the dependent variable in predicting air pollution and proposed a feature optimization process to reduce dimensionality and remove irrelevant features to enhance the prediction of PM2.5, improving the existing LSTM model. The study estimates the concentration of pollutants in the air based on training and highlights the contribution of feature optimization in air quality predictions through feature dimension reductions.

    RESULTS: In this section, the results of predicting the concentration of pollutants (PM2.5, PM10, O3, and CO) in the air are presented in R2 and RMSE. In predicting the PM10 and PM2.5concentration, LSTM performed the best overall high R2values in the four study areas with the R2 values of 0.998, 0.995, 0.918, and 0.993 in Banting, Petaling, Klang and Shah Alam stations, respectively. The study indicated that among the studied pollution markers, PM2.5,PM10, NO2, wind speed and humidity are the most important elements to monitor. By reducing the number of features used in the model the proposed feature optimization process can make the model more interpretable and provide insights into the most critical factor affecting air quality. Findings from this study can aid policymakers in understanding the underlying causes of air pollution and develop more effective smart strategies for reducing pollution levels.

  12. Madni A, Rehman S, Sultan H, Khan MM, Ahmad F, Raza MR, et al.
    AAPS PharmSciTech, 2020 Nov 22;22(1):3.
    PMID: 33221968 DOI: 10.1208/s12249-020-01873-z
    Targeting the small intestine employing nanotechnology has proved to be a more effective way for site-specific drug delivery. The drug targeting to the small intestine can be achieved via nanoparticles for its optimum bioavailability within the systemic circulation. The small intestine is a remarkable candidate for localized drug delivery. The intestine has its unique properties. It has a less harsh environment than the stomach, provides comparatively more retention time, and possesses a greater surface area than other parts of the gastrointestinal tract. This review focuses on elaborating the intestinal barriers and approaches to overcome these barriers for internalizing nanoparticles and adopting different cellular trafficking pathways. We have discussed various factors that contribute to nanocarriers' cellular uptake, including their surface chemistry, surface morphology, and functionalization of nanoparticles. Furthermore, the fate of nanoparticles after their uptake at cellular and subcellular levels is also briefly explained. Finally, we have delineated the strategies that are adopted to determine the cytotoxicity of nanoparticles.
  13. Maluin SM, Jaffar FHF, Osman K, Zulkefli AF, Mat Ros MF, Ibrahim SF
    Reprod Med Biol, 2024;23(1):e12606.
    PMID: 39263384 DOI: 10.1002/rmb2.12606
    PURPOSE: This study aimed to evaluate the protective effects of edible bird nest (EBN) against the detrimental impact of Wi-Fi on male reproductive health. Specifically, it examines whether EBN can mitigate Wi-Fi-induced changes in male reproductive hormones, estrogen receptors (ER), spermatogenesis, and sperm parameters.

    METHODS: Thirty-six adult male rats were divided into six groups (n = 6): Control, Control EBN, Control E2, Wi-Fi, Wi-Fi+EBN, and Wi-Fi+E2. Control EBN and Wi-Fi+EBN groups received 250 mg/kg/day EBN, while Control E2 and Wi-Fi+E2 groups received 12 μg/kg/day E2 for 10 days. Wi-Fi exposure and EBN supplementation lasted eight weeks. Assessments included organ weight, hormone levels (FSH, LH, testosterone, and E2), ERα/ERβ mRNA and protein expression, spermatogenic markers (c-KIT and SCF), and sperm quality.

    RESULTS: Wi-Fi exposure led to decreased FSH, testosterone, ERα mRNA, and sperm quality (concentration, motility, and viability). EBN supplementation restored serum FSH and testosterone levels, increased serum LH levels, and the testosterone/E2 ratio, and normalized mRNA ERα expression. Additionally, EBN increased sperm concentration in Wi-Fi-exposed rats without affecting motility or viability.

    CONCLUSIONS: EBN plays a crucial role in regulating male reproductive hormones and spermatogenesis, leading to improved sperm concentration. This could notably benefit men experiencing oligospermia due to excessive Wi-Fi exposure.

  14. Keng Yoon Y, Ashraf Ali M, Choon TS, Ismail R, Chee Wei A, Suresh Kumar R, et al.
    Biomed Res Int, 2013;2013:926309.
    PMID: 24381946 DOI: 10.1155/2013/926309
    A total of seven novel benzimidazoles were synthesized by a 4-step reaction starting from 4-fluoro-3-nitrobenzoic acid under relatively mild reaction conditions. The synthesized compounds were screened for their antimycobacterial activity against M. tuberculosis H₃₇Rv (MTB-H₃₇Rv) and INH-resistant M. tuberculosis (INHR-MTB) strains using agar dilution method. Three of them displayed good activity with MIC of less than 0.2 μM. Compound ethyl 1-(2-(4-(4-(ethoxycarbonyl)-2-aminophenyl)piperazin-1-yl)ethyl)-2-(4-(5-(4-fluorophenyl)pyridin-3-ylphenyl-1H-benzo[d]imidazole-5-carboxylate (5 g) was found to be the most active with MIC of 0.112 μM against MTB-H₃₇Rv and 6.12 μM against INHR-MTB, respectively.
  15. Abdul Manap AS, Vijayabalan S, Madhavan P, Chia YY, Arya A, Wong EH, et al.
    Drug Target Insights, 2019;13:1177392819866412.
    PMID: 31391778 DOI: 10.1177/1177392819866412
    Alzheimer disease is a neurodegenerative disease that is signified by cognitive decline, memory loss, and erratic behavior. Till date, no cure for Alzheimer exists and the current Alzheimer medications have limited effectiveness. However, herbal medicines may slow down the disease's progression, which may hopefully reduce the number of cases in the years to come. Numerous studies have been done on characterizing the neuroprotective properties from plants belonging to Scrophulariaceae family, particularly Bacopa monnieri and its polyphenolic compounds known as bacosides. This review presents the findings on bacosides in therapeutic plants and their impact on Alzheimer disease pathology. These reports present data on the clinical, cellular activities, phytochemistry, and biological applications that may be used in new drug treatment for Alzheimer disease.
  16. Ahmad H, Ahmad S, Shah SAA, Khan HU, Khan FA, Ali M, et al.
    J Asian Nat Prod Res, 2018 Feb;20(2):172-181.
    PMID: 28463565 DOI: 10.1080/10286020.2017.1319820
    New lycoctonine-type dual cholinesterase inhibitor, swatinine-C (1), along with three known norditerpenoid alkaloids, hohenackerine (2), aconorine (5) and lappaconitine (6) and two synthetically known but phytochemically new benzene derivatives, methyl 2-acetamidobenzoate (3) and methyl 4-[2-(methoxycarbonyl)anilino]-4-oxobutanoate (4), was isolated from the roots of A. laeve. Structures of new and known compounds (1-6) were established on the basis of latest spectroscopic techniques and by close comparison with the data available in literature. In vitro, compounds (1-6) were tested against AChE and BChE inhibitory activities. Compounds 1 and 2 showed competitive inhibition against AChE (IC50 = 3.7 μM, 4.53 μM) and BChE (IC50 = 12.23 μM, 9.94 μM), respectively. Compounds 5 and 6 showed promising noncompetitive type of inhibitory profile against AChE (IC50 = 2.51 and 6.13 μM) only. Compounds 3 and 4 showed weak inhibitory profile against both AChE and BChE.
  17. Ahmad H, Ahmad S, Shah SAA, Latif A, Ali M, Khan FA, et al.
    Bioorg Med Chem, 2017 07 01;25(13):3368-3376.
    PMID: 28457693 DOI: 10.1016/j.bmc.2017.04.022
    Extensive chromatographic separations performed on the basic (pH=8-10) chloroform soluble fraction of Aconitum heterophyllum resulted in the isolation of three new diterpenoid alkaloids, 6β-Methoxy, 9β-dihydroxylheteratisine (1), 1α,11,13β-trihydroxylhetisine (2), 6,15β-dihydroxylhetisine (3), and the known compounds iso-atisine (4), heteratisine (5), hetisinone (6), 19-epi-isoatisine (7), and atidine (8). Structures of the isolated compounds were established by means of mass and NMR spectroscopy as well as single crystal X-ray crystallography. Compounds 1-8 were screened for their antioxidant and enzyme inhibition activities followed by in silico studies to find out the possible inhibitory mechanism of the tested compounds. This work is the first report demonstrating significant antioxidant and anticholinesterase potentials of diterpenoid alkaloids isolated from a natural source.
  18. Ahmad H, Ahmad S, Ali M, Latif A, Shah SAA, Naz H, et al.
    Bioorg Chem, 2018 08;78:427-435.
    PMID: 29698893 DOI: 10.1016/j.bioorg.2018.04.008
    Three new norditerpenoids alkaloids, 1β-hydroxy,14β-acetyl condelphine (1), jadwarine-A (2), jadwarine-B (3) along with two known alkaloids isotalatizidine hydrate (4) and dihydropentagynine (5) were isolated from medicinal plant Delphinium denudatum. The structures of natural products 1-5 were established on the basis of HR-EIMS, 1H and 13C NMR (1D & 2D) spectroscopic data as well as by comparison from literature data. The structures of compound 1 and 4 were also confirmed by single crystal X-ray diffraction studies. In-vitro AChE and BChE enzyme inhibitory activities of compounds 1-5 and molecular docking studies were performed to investigate the possible molecular inhibitory mechanism of the isolated natural products. Compound 2, 4 and 5 showed competitive inhibitory effects by inhibiting AChE and BChE, respectively, while 1 and 3 showed non-competitive inhibition. This work is the first report that provides a supporting evidence about the use of constituents of Delphinium denudatum in cerebral dementia and Alzheimer diseases.
  19. Iftikhar F, Ali Y, Ahmad Kiani F, Fahad Hassan S, Fatima T, Khan A, et al.
    Bioorg Chem, 2017 10;74:53-65.
    PMID: 28753459 DOI: 10.1016/j.bioorg.2017.07.003
    In our previous report, we have identified 3,4-dihydropyrimidine scaffold as promising class of urease inhibitor in a structure based virtual screen (SBVS) experiment. In present study, we attempted to optimize the scaffold by varying C-5 substituent. The elongation of the C-5 chain was achieved by the reaction of C-5 ester with hydrazine leading to C-5 carbohydrazides which were further used as building blocks for the synthesis of fifteen new compounds having diverse moieties. A significantly higher in vitro urease inhibitory activity with IC50 values in submicromolar range was observed for semithiocarbazide derivatives (4a-c, 0.58-0.79µM) and isatin Schiff base derivative 5a (0.23µM). Docking analysis suggests that the synthesized compounds were anchored well in the catalytic site and extending to the entrance of binding pocket and thus restrict the mobility of the flap by interacting with its key amino acid residues. The overall results of urease inhibition have shown that these compounds can be further optimized and developed as lead urease inhibitors.
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